Transfer mechanism



Feb. 11, 1964 v H. L. HOYT TRANSFER MECHANISM 2 Sheets-Sheet 1 Filed May 5. 1961 INVENT OR Herberv L. HOl/I Feb. 11, 1964 H. L. HOYT 3,120,770

- TRANSFER MECHANISM Filed May 5. 1951 2 Sheets-Sheet 2 IN VENTOR Herbert Lv HoL Z' 5 2mm, @ocwoi r ATTORNEY5 United States Patent O 3,120,770 TRANEaFER MECHANISM Herbert L. Hoyt, Waterbury, Conn, assignor, by mesne assignments, to Textron industries, line, a corporation of Delaware Filed May 5, 1961, Ser. No. 108,128 13 (Ilaims. (Cl. 73--99) This invention relates to metal working machines such as headers, nut formers and the like, and particularly to a transfer mechanism for such machines.

In machines of the type noted above, a metal blank is operated on at a number of stations to progressively work the blank. Such stations are provided With cooperating punches and dies and means are further provided for transferring the blank from one operation or station to the next. The means for transferring the blank is commonly referred to as a transfer mechanism in which fingers are arranged to receive and grip a blank ejected from a die by a knock out pin at one station, and transfer the work piece to the next station or die. At this next die the fingers position the blank so it can be pushed out of the fingers by a pusher rod in the punch and into the die, whereupon the next operation is performed.

Transfer mechanisms known to the prior art perform the above described functions quite satisfactorily except where odd shaped blanks i.e. large head to shank diameters, both lengths being equal, are encountered. When such odd shapes are forms din a die, a knock out device cannot dependably maintain control of the blank, for if the blank is knocked out of the die a distance sufiicient to remove the headed portion, the narrow shank portion will enter the large diameter, or large die cavity, thus allowing the blank to tip. Control over the blank will thereby be lost.

To overcome the deficiencies noted above and provide a transfer mechanism which will dependably handle such odd shaped blanks, the present invention, briefly described, relates to a transfer mechanism in which a knock out pin partially ejects the headed portion of the blank into a position to be received by the transfer fingers while a portion of the blank remains in its associated die cavity portion to prevent possible tipping of the blank. The transfer fingers complete the removal of the blank from the die by movement in a plane normal to the die face. The blank is then transferred to the next position by an arcuate movement of the transfer fingers in a plane parallel to the die faces. The blank is inserted in the next die by a second movement of the transfer fingers in a plane normal to a die f ce, this time in the opposite direction or toward the die face. The blank is therefore inserted in the succeeding die without the aid, or necessity, of pusher pins in the punch. The transfer fingers next move along an arcuate path in a plane parallel to the die face in the opposite direction to that in which the blank was transferred to complete a cycle. However, the parallel plane in which the fingers move to complete the cycle is closely adjacent the die faces and therefore spaced from the plane of the fingers while transferring the blank. In the arcuate path completing the cycle the transfer fingers may assume a neutral position halfway between adjacent dies to allow both punches associated with these adjacent dies to operate on each blank simultaneously. In the neutral position, the transfer fingers will not interfere with the operation of the punches. From the neutral position the fingers move to pick up another blank and repeat the cycle described.

Means are provided to adjust the stroke of the arcuate movement of the fingers, by adjusting the effective length of the transfer arm, so that the stroke of the transfer arm is equal to the center to center distance between dies.

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Adjustment is also provided in the in and out or normal movement of the transfer fingers relative to the die as fully described in connection with the description of the drawings.

In view of the foregoing, an object of this invention is to provide a transfer mechanism for handling odd shaped blanks in heading machines, nut formers and like machines.

Another object of this invention is to provide a new and useful transfer mechanism comprising a minimum number of elements, which are economically manufactured, assembled and maintained.

Still another object of this invention is to provide a new and useful transfer mechanism which is easily and accurately adjusted to handle various sized blanks.

A further object of this invention is to provide a new and useful transfer mechanism which inserts a blank in a die without the assistance of pusher pins.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

A full understanding of the invention, its objects and advantages, will be apparent from the following detailed description taken in connection with accompanying drawings of a presently preferred embodiment, in which:

FIG. 1 is a front e-levational view of the die block of a header machine, or the like, showing the transfer mechanism according to the invention applied thereto;

FIG. 2 is a top plan view of the transfer mechanism illustrated in FIG. 1;

PEG. 3 is an end view of the transfer mechanism with parts in section.

Only two dies or stations, A and B, are shown in the drawings, the pair of dies being provided with transfer fingers. However, it will be appreciated that several pairs of fingers, accompanying transfer mechanisms, and associated dies may be used in practice. Only one transfer finger and mechanism is shown for a clear understanding and concise description of the invention.

To illustrate the invention, FIG. 1 shows a portion or" the frame It) of a progressive header machine having a die bed 11. A cut off station 12, wherein a blank is cut from stock, is shown in the die bed. The cut of mechanism, which forms no part of this invention, delivers a blank to the die A, the blank being operated on in known manner by a punch (not shown) cooperating with die A. T he second operation is performed on the blank in die B. Operation of the punches (not shown) associated with dies A and B is performed simultaneously at which time the fingers 33 are in the position shown in FIG. 1.

FIG. 1 best illustrates the cross transfer motion or lateral motion parallel to the face of the dies, performed by the transfer fingers. As seen by the phantom view of the fingers such motion is performed by oscillating the fingers 13.

The transfer fingers 13 are biased to gripping or clamping position in any suitable manner, one of which is shown, and are secured or carried by an oscillatably mounted transfer arm -14. The free ends of the fingers are shaped so as to be automatically opened upon engagement with a blank. That is, since the fingers, travelling from die B, to the neutral position shown, and then to die A to pick up a blank, travel in an arcuate path C, the fingers approach a blank in die A in the vertical plane of the exposed headed portion of the blank. Conversely, once the fingers 13 have placed a blank in die B so that the headed portion is partially in the header die cavity, they automatically open since their travel away from die 13 is upwardly in the vertical plane of the headed portion of the blank.

As indicated above, the transfer arm 14, carrying fingers 13, is oscillatably mounted (as best seen in FIG. 3

and described in connection therewith) in a carrier or transfer mechanism frame 16 fixed to the base 1% of the machine.

The driving mechanism for oscillating the transfer arm 14 comprises, a cam 17 which may be adjustably secured on the side shaft of the machine in known manner. A cam roller '18, at one end of a cam lever 19, is urged, by a spring as shown, or other suitable means, against the cam 17. The lever 19 is pivotally oscillated about point 21} as is well known. A link 21, adjustably secured to the other end of the lever 19, is pivotally secured in driving relation with a notched rack 22. As indicated in the drawings, the link 21 is adjustable lengthwise. The rack 22 is therefore driven or reciprocated right and left as shown in FIG. 1. As best seen in FIG. 3, the rack 22 oscillatably drives a pinion 23, a crank shaft 24, and an offset crank 25. The crank pin 26 is pivotally secured or journalled in the transfer arm 14 in any suitable manner. The pinion 23, shaft 24, crank 25 and crank pin 26 may be integral parts.

Referring again to FIG. 1, it will be seen that the crank pin 26 is secured to the transfer arm 14 intermediate the end thereof supporting fingers 13 and the other end of the transfer arm which is slidably supported in a pivotal block 27. Block 27 is connected to or integral with shaft 28 journalled in a bearing block 29 as best seen in FIG. 3. A push-pull screw 30 is provided to adjust the position of block 29 and thus block 27 relative to the position of crank pin 26 on transfer arm 14. Adjustment of the block 27 toward or from crank shaft 24 will vary the length 'of the arc C the transfer arm travels and thereby accurately adjust the stroke of the transfer arm 14 to the center to center distance between dies A and B. The length and/ or pivot point of the transfer arm 14 is therefore controlled by block 27 and the arm 14 is slidably held in the block by the crank pin 26. The extreme cross transfer positional relationships between transfer arm 14 and pivotal block 27 are shown by the full and phantom lines showing of these parts in FIG. 1. The in and out, or normal position of fingers 13, arm 14 and block 27 is shown by the phantom lines of FIG. 3.

It will be apparent from FIG. 1 and the above description thereof that rotation of cam 17, oscillates the lever 19 to impart reciprocal motion to the link 21 and rack 22. Reciprocal motion of the rack 22 oscillates the crank pin 26 connected to the transfer arm 14. The oscillating transfer arm, slideably secured in block 27 at one end and carrying fingers 13 at the other end, causes the fingers 13 to move over an arcuate, cross transfer path C between stations A and B.

The foregoing description of the drawing discloses the mechanism causing the fingers to follow a lateral, or arcuate cross transfer motion, parallel to the face of the dies.

The other basic motion of the fingers 13, i.e. the motion normal to the face of the dies, or in and out transfer, is best illustrated in FIG. 3 and will be described in connection therewith.

Referring therefore to FIG. 3 it will be seen that pinion 23 is laterally movable relative to the rack 22 within a suitable space provided in the transfer frame 16, between the journal portions of crank shaft 24. Thus, the crank shaft 24, crank offset 25, and crank pin 26 are free to move, or reciprocate, from right to left as seen in FIG. 3. A spool 32, integral with the free end of crank shaft 24, is reciprocally driven by a lug 34 to impart such motion to crank 25 and therefore also reciprocate transfer arm 14 normal to the plane of the die faces. It is noted that the arrangement of spool 32 and lug 34 allows crank shaft 24 to rotate while being oscillated.

The guide block 27, associated shaft 28 and spool 31 are similarly reciprocated by means of a lug 33 while pivoting or oscillating in unison with the transfer arm 1%, the operation of which was described above. It will be apparent therefore that transfer arm 14 is held at two 4 portions therealong, by the crank 25 and block 27, during both its reciprocal and oscillatory motions to provide positive and accurate control of arm 14 and thus transfer fingers 13.

As in FIG. 1, the phantom lines of FIG. 3 indicate extreme reciprocal positions of arm 14 andfingers 13.

Reciprocal movement of the arm 14, block 27 and fingers 13, as a unit, normal to the face of dies A and B, is accomplished by reciprocation of spools 31 and 32 operatively associated with opposed lugs 33 and 34 suitably connected to right angle lever 35 best seen in FIG. 2.

As best illustrated in FIG. 2; lever 35, also shown in part in FIGS. 1 and 3, is pivotally secured at 36 to the carrier frame 16. One arm of the lever 35 carries the lugs 33, 34 and the other arm of lever 35 is secured to a link 37 at 41. Link 37 is similar to link 21 and is driven separately by a second cam 38. Cams 38 and 17 are both adjustably fixed to the side shaft of the machine.

The earns 17 and 38 may be rotatably repositioned on the side shaft to vary the relative positions thereof and change the timing of fingers 13 in either or both of the basic movements thereof. Intermediate the cam 38 and link 37 is a cam roller 39 held against cam 33 and rotatably mounted on lever as which is in turn, pivotally secured in well known manner to link 37 remote from right angle lever 35.

The movement of the transfer arm 14, block 27 and fingers 13 may be adjusted as noted above by relative displacement of cams 17 and 38. Additionally or alternatively, link 37 may be connected at either point 41 or 4-2 on lever 35. Also, similarly separate or spaced connection points may be provided on lever 40 at the other end of link 37.

It will be apparent from FIGS. 2 and 3, taken in the light of the foregoing description thereof, that rotation of cam 38 reciprocates link 3'7 to oscillate the right-anglelever 35 which imparts simultaneous reciprocal motion to both block 27 and crank 25 by virtue of spools 3 1 and 32 activated by the lugs 33 and 34- reciprocally driven by the lever 35.

It will be clear from the foregoing that the composite motion of the transfer fingers allows them to receive and grip a headed blank partially ejected from die A, move the blank normal to the face of die A to completely remove the blank therefrom. The blank may then be transferred in a plane parallel to the face of dies A and B, or if the dies are not coplanar, in an oblique angled plane over a curved path to the next station. At the succeeding station the fingers insert the blank in the associated die and withdraw to a neutral position clear of the punches and close to the die faces in a plane spaced from the arcuate transfer plane.

The fingers 13 may be given various motions by varying the surface of cams 17 and 38 of the transfer mechanism and adjusting these cams relative to one another. The versatility of the arrangement according to the invention will be apparent to those skilled in the art. The motion described above, however, is presently preferred for such machines as progressive headers, nut formers and the like.

It will thus be seen that the objects set forth above, among those made apparent from the preceding descrip tion, are efiiciently attained and, since certain changes may be made in the constructions set forth, such as indicated above, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also understood that the following claims are intended to cover all the generic and specific features of the invention described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by letters patent is:

1. In a machine having a frame and at least two dies, a transfer mechanism for transferring a workpiece between the dies comprising a transfer arm pivotally and slidably mounted to said frame, transfer fingers mounted to said transfer arm, first means cooperatively associated with said transfer arm to pivotally oscillate said arm through a continuous are forming a plane substantially parallel to the faces of the dies, and second means cooperatively associated with said transfer arm to slidably move said transfer arm in timed relation with the pivotal oscillations along a line substantially perpendicular to the faces of the dies.

2. In a machine having a frame and at least two dies supported by the frame, a transfer mechanism for transferring a workpiece between the dies comprising an eccentric pivotally and slidably mounted to said frame, a transfer arm pivotally mounted intermediate its ends to said eccentric, transfer fingers mounted to one end of said transfer arm, a guide pivotally and slidably mounted to said frame, the other end of said transfer arm slidably engaging said guide, first means for pivotally oscillating said eccentric to move said transfer arm in a plane substantially parallel to the faces of the dies, and second means for slidably moving said transfer arm in timed relation with the pivotal oscillations along a line substantially perpendicular to the faces of the dies.

3. In a machine having a frame and at least two dies supported by the frame, a transfer mechanism for transferring a workpiece between the dies comprising an eccentric pivotally and slidably mounted to said frame, a transfer arm pivotally mounted intermediate its ends to said eccentric, transfer fingers mounted to one end of said transfer arm, a guide pivotally and slidably mounted to said frame, the other end of said transfer arm slidably engaging said guide, first means for pivotally oscillating said eccentric to move said transfer arm in a plane substantially parallel to the faces of the dies, and second means for slidably moving said eccentric and said guide in timed relation to the pivotal oscillations to effect movement of said transfer arm along a line substantially perpendicular to the faces of the dies.

4. In a machine having a frame and at least two dies supported by the frame, a transfer mechanism for transferring a workpiece between the dies comprising a shaft rot-atably and slidably journalled in said frame, a pinion secured on said shaft, an eccentric mounted to said shaft, a transfer arm pivotally mounted intermediate its ends to said eccentric, transfer fingers mounted to one end of said transfer arm, a guide pivotally and slidably mounted to said frame, the other end of said transfer arm slidably engaging said guide, a rack slidably mounted in said frame and cooperatively engaging said pinion, first means for linearly reciprocating said rack to oscillate said transfer arm in a plane substantially parallel to the faws of the dies, and second means for slidably moving said shaft and said guide in timed relation with the movement of said rack to move said transfer arm along a line substantially perpendicular to the faces of the dies.

5. In a machine having a frame and at least two dies supported by the frame, a transfer mechanism for transferring a workpiece between the dies comprising an cecentric pivotally and slidably mounted to said frame, a transfer arm pivotally mounted intermediate its ends to said eccentric, transfer fingers mounted to one end of said transfer arm, a guide pivotally and slidably mounted to said frame, the other end of said transfer arm slidably engaging said guide, first means for pivotally oscillating said eccentric to move said transfer arm through a continuous are forming a plane substantially parallel to the faces of the dies, second means for slidably moving said eccentric and said guide in timed relation to the pivotal oscillations to effect movement of said transfer arm along a line substantially perpendicular to the faces of the dies, and means for adjusting the position of said guide toward and from said eccentric to adjust the length of are through which said transfer arm oscillates.

6. In a machine having a frame and at least two dies supported by the frame, a transfer mechanism for transferring a workpiece between the dies comprising a first shaft rotatably and slidably journalled in said frame, a pinion secured on said shaft, an eccentric mounted to said shaft, a transfer arm pivotally mounted intermediate its ends to said eccentric, transfer fingers mounted to one end of said transfer arm, a second shaft rotatably and slidably journalled in said frame, a guide mounted to said second shaft, the other end of said transfer arm slidably engaging said guide, a rack slidably mounted in said frame and cooperatively engaging said pinion, first means for linearly reciprocating said rack to oscillate said transfer arm in a plane substantially parallel to the faces of the dies, and second means for slidably moving said first and second shafts in timed relation with the movement of said rack to move said transfer arm along a line substantially perpendicular to the faces of the dies.

7. The structure defined in claim 6, and further including means for moving said second shaft and the guide mounted thereto toward and from said first shaft to adjust the distance between the ends of the oscillatory movement of said transfer arm.

8. In a machine having a frame and at least two dies supported by the frame, a transfer mechanism for transferring a workpiece between the dies comprising a first shaft rotatably and slidably journalled in said frame, a pinion secured on said first shaft, an eccentric mounted to said first shaft, a transfer arm pivotally mounted intermediate its ends to said eccentric, transfer fingers mounted to one end of said transfer arm, a second shaft rotatably and slidably journalled in said frame, a guide mounted on said second shaft, the other end of said transfer arm slidably engaging said guide, a rack slidably mounted in said frame and cooperatively engaging said pinion, first means for linearly reciprocating said rack to oscillate said transfer arm along an are forming a plane substantially parallel to the faces of the dies, a spool mounted to each of said shafts, a single lug cooperatively engaging each spool, and second means for moving said lug along a line parallel to the axes of said first and second shafts for slidably moving said eccentric and said guide in timed relation with the movement of said rack to move said transfer arm along a line substantially perpendicular to the faces of the dies.

9. The structure defined in claim 8, and further including means for moving said second shaft toward and from said first shaft to adjust the length of arc through which said transfer arm is oscillated.

10. The structure defined in claim 8, wherein said first means comprises a link, a bell crank pivoted intermediate its ends to said frame, one end of said link being pivoted to said rack and the other end thereof being pivoted to one end of said bell crank, a cam follower pivotally mounted to the other end of said bell crank, a rotating shaft journalled in the machine, a cam secured on said rotating shaft, and means acting against said bell crank for urging said cam follower into contact with the surface of said cam.

11. The structure defined in claim 10, wherein said link further includes means for adjusting the distance between its pivotal ends for adjusting the position of said transfer fingers with relation to said dies.

12. The structure defined in claim 8, wherein said second means includes a rotating shaft journalled in the machine, a cam secured to said rotating shaft, and means cooperatively associated with said cam and said lug to linearly reciprocate said lug in response to the changing profile of said cam.

13. In a machine having a frame and a plurality of dies, a plurality of transfer mechanisms for transferring workpieces between the dies, a transfer mechanism being provided between each adjacent die pair, comprising a 7 transfer arm pivotally and slidably mounted to said frame, transfer fingers mounted to said transfer arm, first means cooperatively associated with said transfer arm to pi otally oscillate said arm through a continuous arc forming a plane substantially parallel to the face of the adjacent die pair, and secondnieans cooperatively associated with said transfer arm to slidably move said transfer Ref erences Cited in the file of this patent UNITED STATES PATENTS Burbank Dec. 27, 1932 De Loe Mar. 4, 1958 

1. IN A MACHINE HAVING A FRAME AND AT LEAST TWO DIES, A TRANSFER MECHANISM FOR TRANSFERRING A WORKPIECE BETWEEN THE DIES COMPRISING A TRANSFER ARM PIVOTALLY AND SLIDABLY MOUNTED TO SAID FRAME, TRANSFER FINGERS MOUNTED TO SAID TRANSFER ARM, FIRST MEANS COOPERATIVELY ASSOCIATED WITH SAID TRANSFER ARM TO PIVOTALLY OSCILLATE SAID ARM THROUGH A CONTINUOUS ARC FORMING A PLANE SUBSTANTIALLY PARALLEL TO THE FACES OF THE DIES, AND SECOND MEANS COOPERATIVELY ASSOCIATED WITH SAID TRANSFER ARM TO SLIDABLY MOVE SAID TRANSFER ARM IN TIMED RELATION WITH THE PIVOTAL OSCILLA- 